Homopolar generator



Aug. 13, 1935. w. sYKEs HOMOPOLAR GENERATOR Filed Aug. 23. 1930 C5Sheets-Sheet 1 9m, @Wa RN WWW@ V :.ln- E lllnllnll Aug. 13, 1935. w.sYKEs 2,011,349

HOMOPOLR GENERATOR Filed Aug. 2:5, 1930 s sheets-sheet 2 Nw wurm. c L YN x LN T III wv mmm 3 a @rw/@ff Aug. 13, 1935. w. sYKEs HOMOPOLARGENERATOR s sheets-sheet s Filed Aug. 23, 1930 Patented Aug. 13, 1935UNITEDV STATES noMoPoLAa cli-:Neuron Wilfred Sykes, Chicago, Ill.,aosignor to Inland Steel Company, Chicago, lll., .a corporation ofDelaware Application August 23, 1930, Serial No. 477,408

11 Claims.

My invention relates to direct current generators of the homopolar typefor the supplying of high amperage low voltage current more particularlyfor performing welding operations.

As a preface to the following description it may be stated that ashomopolar direct generators have been hitherto constructed, it has notbeen possible to build a practical machine approximating the capacitiesrequired for welding especially in the producing of so-called light-wallpipe; namely, current production of the order oi 150,000 to 200,000amperes, or an approximate thereto, at a low potential of say to 15volts for welding large pipe, due to the high losses in the collectorelement oi.' the generator and comprising those due to friction of thebrushes and the contact between the brushes and the collector, producingheat of such a high degree that the brushes and collector burn, soonrendering the generator inoperative.

My primary object is to provide a construction of homopolar generatorwhich shall be practical for the generating of such large amperagedirect currents at a relatively low potential.

Still another object is to provide a construction of homopolar directcurrent generator which will react more quickly to changes in the eldstrength of the generator.

Referring to the accompanying drawings:

Figure l is a view in longitudinal sectional elevation oi one-half of ahomopolar direct current generator constructed in accordance with myinvention.

Figure 2 is a similar view of the other half of the generator.

such as cast-steel having a ring member 8 rising crosswise therefrommidway between its ends and provided with a circular series of arms 9which extend therefrom lengthwise of the casting in opposite directionsand are connected-at their outer ends with ring members I0 extendingsubstantially parallel with the ring member 8, this construction forminga magnetic circuit for the conducting of the magnetic ux from thecentral part of a rotating core, hereinafter described, to its ends.

The generator also comprises field coils for providing excitation, thesecoils which are stationary being represented at II and shown as carriedon suitable brackets I2 attached to the rings I0. '5

The rotating core of the machine which is represented at I 3 and isformed of magnetic material and suitably journalled in uprights I4rising from the ends of the casting 1, is provided midway be-k tween itsends with an annular flange portion I5 forming an annular enlargementpositioned within the central opening I6 in the ring member 0, theopening I6 being of such a diameter as to provide running clearance tothe rotating core I3.

Mounted on the core I3 at opposite sides of its annular enlargement I5and insulated from the core, by the insulation represented at I1, aretubular current-collector members I8 as for example, and preferably, ofcopper, the adjacent ends of these collector members having annularanges I9, and each collector member I8 being preferably formed of aplurality of segments I8l insulated from each other as represented atIBI. These collector members are electrically connected together bymeans of a circular series of copper rods connected at their ends withthe flanges I9 and extending through openings 2| in the enlargement I5of the core I3 and insulated from the walls of the openings 2| byinsulating sleeves represented at 22.

Cooperating with the collector members I0 are two sets ofcurrent-conducting brushes represented at 23, these sets of brushesbeing supported on two sets of rods 24 each surrounding the core I3 andshown as arranged in a circular series concentric with the axis of thecore. The rods 24 are supported, at one end in brackets 25 of insulatingmaterial set into, and secured by screws 25* in recesses 26 in the facesof the ring member 8 and extend at their outer ends through openings inthe end members I0 from the walls of which they are insulated, the outerends of the rods 24 being connected with collector rings 21 locatedoutside tm magnetic field and concentrically surrounding the outer endsof the core I3 and spaced therefrom, these collector rings constitutingthe terminals of the generator.

In the construction shown supplemental, graphite brushes, represented at28 are provided for contacting with the collector members I8, thesebrushes being shown as supported on the rod extensions 29 of brackets 30secured to the arms 9.

Inasmuch as a generator, as described, in its operation for producing acurrent oi.' great amperage and at a relatively low potential generatessuch a relatively high degree of heat that unless dissipated renders themachine impractical for continuous operation, I provide means forartiflcially internally cooling the collector members I3 thereby addingto the normal cooling effect produced by ordinary windage.

'I'he means shown for this purpose comprise a conduit 3I extendingcentrally in the core I3, one end of this conduit being connected with atube 32 journalled in the stufllng box portion 33 of a head 34 securedto one of the journal boxes in which the core I3 rotates, the stuing box33 being connected with a pipe 35 which would lead to any suitablesource of supply of fluid, such as oil or water, or compressed air, ifdesired, in the case of small machines, the end of the core I3containing the pipe 32 being recessed as represented at 36 to provide achamber surrounding the pipe 32 out of communication with the conduit3I, the outer end of the chamber 36 opening into a chamber 31 in thehead 34 provided with an outlet 38 through which the cooling fluidsupplied to the collector members I3, as hereinafter described,discharges.

Each collector-member segment |88' contains a conduit 33 of coil-likeform the inlet end 40 of which connects with a nipple 4l connected by aflexible rubber tum 41 with a pipe member 43, the members 43, one foreach conduit coil 39, being disposed in a circular series about the coreI3 and secured to the outer surface thereof and c ommunicating,respectively, with cross passages 44 in the core and opening into theconduit 3i. The outlet ends of the coil conduits 39 and represented at45 are likewise connected with nipples 46 connected by rubber tubing 4lto pipe members 4B secured to the periphery of the core I3 and com-nmunicating with cross passages 45 in the core which open into passages Din the core which are closed at one end and open at their opposite end,through cross-passages 5I, into the chamber 36.

It will thus be understood from the foregoing description that thecooling fiuid supplied to the pipe 35 enters each conduit coil 39through its inlet and thence discharges through its outlet to theexhaust passage 50 in the core I3 from which latter it passes to theoutlet 33, the cooling fiuid thus flowing through the collector membersI8 serving to eifectually and rapidly remove therefrom the heatgenerated in the operation of the machine, thereby preventingobjectionable accumulation of the heat which results when the originalgood brush contact ceases.

The collector members I8 mounted on the core I3 as stated, are free toexpand when they become heated by the operation of the machine, in adirection axially of the core thereby preventing any tendency todistortion of the members I8 and which if it did occur wouldobjectionably affect the collection of the current.

The features of locating the collecting rings 21 outside of the mainmagnetic circuit and that of subdividing the collector members asdescribed, are of advantage as the objectionable damping action of therelatively heavy copper conductors is greatly reduced and the field iscaused to be quickly responsive to regulating means which may beprovided.

It may be added that the parts of each collector member I3 are of thesame polarity and of substantially the same potential, speaking in ageneral sense. Those skilled in the art will realize oi' course thatthere may be some drop in potential longitudinally in collector membersof considerable length as well as local variations due to eddy currentsor other causes.

While I have illustrated and described a particular construction ofgenerator, I do not Wish to be understood as intending to limit myinvention thereto as various changes and alterations in structures shownmay be made thereinwithout departing from the spirit of my invention.

What I claim as new, and desire to secure by Letters Patent, is:

1. A direct current generator comprising a field member, a rotatablecore, and a collector member, said core containing inlet and outletconduits extending lengthwise thereof and said collector membercontaining a conduit communicating at opposite ends with said inlet andoutlet conduits, respectively..

2. A direct current generator comprising' a eld member, a rotatable coreand a collector member, said core containing inlet and outlet conduitsextending lengthwise thereof and said collector member containing aplurality of conduits each communicating at its opposite ends with saidinlet and outlet conduits, respectively.

3. A homopolar generator comprising a field member; a rotatable core; ametal collector member having a conduit for circulation of coolingliquid closed against the escape of liquid therefrom to the outercircumference of the collector member by the metal of said member; andmeans to provide such circulation.

4. A homopolar generator comprising a field member; a rotatable core; acollector member having a conduit for circulation of cooling liquidformed in and completely surrounded by integral material of thecollector; and means to provide such circulation.

5. A homopolar generator comprising a field member; a rotatable core; ametal collector member having a conduit for circulation of coolingliquid formed in, and completely surrounded by, the metal of thecollector member; and means to provide such circulation.

6. A homopolar generator comprising a field member; a rotatable core; anannular collector member having a conduit for circulation of coolingliquid formed in the material thereof and wholly confined between theinner and outer surface thereof; and means to provide such circulation.

7. A homopolar generator comprising a field member; a rotatable core; acollector member comprising an integral annular ring having a conduitfor circulation of a cooling liquid formed in the material thereof andWholly confined between the inner and outer surfaces of the ring; andmeans to provide such circulation.

8. A homopolar generator comprising a field member; a rotatable core; acollector rotatable with the core; a plurality of brushes of likepolarity and potentials contacting the surface of the collector; andmeans to prevent roughening of the collector and brushes by electricalcontact losses comprising means to circulate cooling liquid within thebody of said collector.

9. A homopolar generator comprising a field member, a rotatable core, acollector member all parts of which are of substantially the samepotential, said core and collector member containing conduitsfor thecirculation therethrough of a cooling liquid, and means for circulatingcooling liquid through said conduits.

10. A homopolar generator comprising a field member, a rotatable core,and a collector member all parts of which are of substantially the samepotential. said core and collector member containing communicatingconduits tor the circulation therethrough o! a cooling fluid, saidconduit in said collector being of general coll form.

ll. A homopolar generator comprising a neld member, a rotatable core anda collector member all ports ot which are of substantially the samepotential, said core containing inlet and outlet conduits extendinglengthwise theteot and said collector member containing a plurality 0icduits each communicating at its opposite ends with said inlet andoutlet conduits. respectively said conduits in said collector memberbeing c: general coil form.

WILFRID m.

